MUD Security directory
A specialized directory of security tools, libraries, and frameworks designed to assist MUD administrators in hardening legacy C/C++ codebases, protecting player credentials, and mitigating network-level attacks on game servers.
Showing 10 of 10 entries
Fail2Ban
open-sourceIntrusion prevention software that protects MUD servers from brute-force attacks on SSH and custom game ports by monitoring log files.
Pros
- + Automated IP banning based on failed login attempts
- + Highly configurable for custom MUD log formats
- + Low system resource overhead
Cons
- − Requires correctly configured regex for custom logs
- − Can lead to accidental lockouts for players with unstable connections
Flawfinder
open-sourceStatic analysis tool that examines C/C++ source code to identify potential security vulnerabilities like buffer overflows and format string exploits common in legacy MUD engines.
Pros
- + Specifically targets common C-based security risks
- + Generates reports prioritized by risk level
- + No compilation required to run analysis
Cons
- − Produces false positives requiring manual review
- − Does not catch complex logic-based exploits
Argon2 C Implementation
open-sourceThe reference C implementation of the Argon2 hashing algorithm, recommended for replacing legacy plaintext or MD5 password storage in MUD codebases.
Pros
- + Resistant to GPU-based cracking attempts
- + Configurable memory and time cost parameters
- + Winner of the Password Hashing Competition
Cons
- − Requires integration into legacy C source code
- − Higher CPU usage during login compared to simple hashes
Valgrind Memcheck
open-sourceA memory debugging tool used to detect memory leaks and buffer overflows in MUD servers, preventing crashes and potential remote code execution.
Pros
- + Identifies precise lines of code causing memory corruption
- + Essential for debugging complex C pointers in MUD engines
- + Tracks use of uninitialized memory
Cons
- − Significantly slows down the execution of the server
- − High memory usage during testing sessions
Cloudflare Spectrum
freemiumA reverse proxy service that provides DDoS protection and traffic acceleration for TCP-based protocols like Telnet used by MUDs.
Pros
- + Hides the origin IP of the MUD server
- + Mitigates large-scale volumetric DDoS attacks
- + Global edge network reduces latency for distant players
Cons
- − Free tier limits may be restrictive for high-traffic games
- − Requires technical DNS and proxy configuration
Lynis
open-sourceA security auditing tool for Linux systems that provides a comprehensive health scan and hardening recommendations for MUD hosting environments.
Pros
- + Scans for misconfigured file permissions
- + Checks for outdated packages and vulnerable kernels
- + Provides actionable security scores and tips
Cons
- − Only audits the OS, not the MUD application code
- − Requires root privileges for a full scan
UFW (Uncomplicated Firewall)
open-sourceA user-friendly interface for managing iptables, essential for restricting server access to only necessary MUD and management ports.
Pros
- + Simple syntax for opening MUD ports (e.g., 4000, 23)
- + Easily rate-limit connections to prevent socket exhaustion
- + Integrated with most modern Linux distributions
Cons
- − Less granular than raw iptables rules
- − Requires manual setup of logging for analysis
Libsodium
open-sourceA modern, easy-to-use software library for encryption, decryption, and signatures, ideal for securing MUD-to-MUD communications or inter-process data.
Pros
- + High-level API prevents common cryptographic implementation errors
- + Extremely portable across different OS environments
- + Regularly audited for security vulnerabilities
Cons
- − Adds an external dependency to the MUD build process
- − Overkill for simple password hashing if only Argon2 is needed
AIDE (Advanced Intrusion Detection Environment)
open-sourceA file integrity checker that creates a database of system files to detect unauthorized changes following a server breach.
Pros
- + Detects modifications to game binaries and configuration files
- + Provides proof of system compromise
- + Runs as a scheduled task with minimal overhead
Cons
- − Database must be updated manually after legitimate updates
- − Does not prevent the intrusion, only detects it after the fact
Wireshark
open-sourceA network protocol analyzer used to inspect Telnet traffic for cleartext sensitive data and to debug malformed packet exploits.
Pros
- + Deep inspection of Telnet and SSH handshake protocols
- + Helps identify source of malformed packet attacks
- + Useful for verifying that sensitive data isn't being leaked
Cons
- − Steep learning curve for interpreting packet captures
- − Requires capturing traffic on the server or a mirror port
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